Preheat your oven to 180°C (350°F). Line a baking tray with parchment paper. This prevents cookies from sticking and helps even baking.

In a bowl, beat butter, brown sugar and white sugar together. Mix until light and fluffy. This step gives cookies a soft and rich texture.

Add eggs one at a time. Mix well after each egg. Then add vanilla extract. Stir until everything becomes smooth and creamy.

In another bowl, combine flour, baking soda, salt and cinnamon. Mix well so all dry ingredients are evenly spread.

Slowly add dry ingredients into the wet mixture. Stir gently until combined. Do not overmix. This keeps cookies soft and chewy.

Add rolled oats and optional raisins or chocolate chips. Mix gently. The dough will be thick and slightly sticky.

Take small spoonfuls of dough. Place them on the baking tray. Leave space between each cookie for spreading during baking.

Bake for 10–12 minutes or until edges are golden. The center should look slightly soft. Do not overbake for best texture.

Let cookies cool on the tray for 5 minutes. Then move them to a cooling rack. They will firm up as they cool.